Near a corner of the Circle A Food Store, to the left of the door, a small surveillance camera hangs off the low brick building, pointed down from a spot just below the roof. Slightly askew, it records people and cars coming and going, a slow routine in grainy gray monochrome.

Except for July 19, during 20 charged seconds that broke the monotonyand cast the convenience store into a roiling national debate. About 3 p.m., 28-year-old Markeis McGlockton walked outside and found another man, 48-year-old Michael Drejka, arguing with his girlfriend.

The shooting has started yet another political battle over Florida’s stand your ground law, but this time, experts say, it’s different. Like the videos of police-involved shootings that swept across America in recent years — boosting the Black Lives Matter movement and spreading outcry over racial injustice — the footage has made an abstract legal issue hypervisible.

"People can talk about stand your ground, they can come up with examples, they can say, ‘Well I heard about this one, I read about this one in the news,’ " said University of South Carolina law professor Seth Stoughton. "It’s different when you can see it on video."

The weeks after McGlockton died were hectic. Marches, news conferences, a visit to a Clearwater church from the Rev. Al Sharpton, but no arrest. The reason, Pinellas Sheriff Bob Gualtieri said, was stand your ground.

The controversial self-defense law, which affords the chance for immunity from prosecution to people who assert they used force while in fear for their life or serious injury, made it so deputies could not arrest Drejka, the sheriff said. Instead, he handed the case to prosecutors, who later charged Drejka with manslaughter.

But the incident took on a new dimension as soon as Gualtieri invoked stand your ground.

The law had touched off political and legal conflagrations before — whether it was invoked during trials or not. First there was the deadly shooting of Trayvon Martin by a neighborhood watch volunteer, George Zimmerman, in Sanford. There was the case of Curtis Reeves, a retired police officer who shot and killed another man during an argument in a Pasco County movie theater. There was Michael Dunn, who shot and killed Jordan Davis at a Jacksonville gas station after confronting the teen and his friends about loud music.

None of those cases, however, involved clear public video like the one that shows Drejka shoot McGlockton.

"In the Trayvon Martin case, Zimmerman is the only one who gets to say how that went down," said University of Miami law professor Mary Anne Franks. "There’s so many competing stories, especially when someone dies."

In the latest shooting, she said, people are left with more than just conflicting witness testimony to decipher. "That’s one of the reasons why this is going to be different," Franks said.

Caroline Light, a Harvard professor who wrote a book about self-defense, said video changes the discussion.

"Typically you have the word of the survivor when there are two involved, and there are no witnesses," she said. "There wouldn’t be the same visual dramatization that helps us put things into perspective."

Stoughton, the South Carolina law professor who is also a frequent commentator on police shooting videos, said the McGlockton case has some parallels to the recordings of officer-involved violence.

"When you have a lethal shooting you have he-said and he’s-dead, so you only get one story. When you only have one story, it’s fairly easy to come to one conclusion," said Stoughton, a former Tallahassee police officer. "Video injects a whole new interpretation .... that tells a totally different story, or the same story from a different perspective."

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The surveillance footage of Drejka shooting McGlockton is already a key part of the legal case against him. A detective wrote that investigators have analyzed the footage repeatedly, measuring the distance and movements between the men in the moments before the shooting.

Pinellas-Pasco State Attorney Bernie McCabe has signaled that the video is critical for prosecutors.

But experts cautioned against viewing the recording as a definitive account of the incident, something the sheriff has acknowledged repeatedly since announcing he would not initially arrest Drejka.

"The perception is that watching a video makes you an eyewitness to that event. It has a visceral impact on how you perceive that incident," Stoughton said. "It’s also wrong. You are not in fact an eyewitness to an event just because you watched a video."

Many surveillance recordings, for instance, do not have sound — including the footage in the McGlockton case. Cameras are also typically anchored to a fixed point.

"Video shows us a two-dimensional representation of a three-dimensional action from one and only one perspective," said David Klinger, a criminology professor at the University of Missouri-St. Louis and former police officer. "We can get sucked into this one piece of evidence because we are visual creatures, humans. ... We always have to be careful not to believe that we have everything that we need to know just by seeing a particular surveillance video."